Daniel Montenegro

Expression patterns of microRNAs in the chorioamniotic membranes: a role for microRNAs in human pregnancy and parturition.

MicroRNAs (miRNAs) are involved in the post‐transcriptional regulation of gene expression during development. This study was performed to determine gestational age‐dependent changes in miRNA expression in the chorioamniotic membranes and to assess the significance of miRNAs in human pregnancy and parturition. The expression profile of 455 miRNAs was compared between patients at term without labour (TNL: n = 10), in labour (TL: n = 10), and preterm labour (PTL: n = 10) using microarrays. A total of 39 miRNAs were differentially expressed between term and preterm cases, of which 31 (79.5%) were down‐regulated at term. Expression of ten miRNAs, including miR‐338, differentially expressed between PTL and TL groups was decreased at term. Computational analyses using miRBase Targets have identified PLA2G4B, a phospholipase implicated in parturition, as a putative target of miR‐338. Inhibition of endogenous miR‐338 with anti‐miR‐338 increased the mRNA and protein expression of PLA2G4B in decidual cells. Luciferase assay with reporter constructs confirmed that the suppression of PLA2G4B occurs through binding of miR‐338 to the 3′UTR of PLA2G4B. Interestingly, the expression of Dicer, a key miRNA‐processing enzyme, was markedly decreased at term, particularly with labour in the chorioamniotic membranes. Collectively, the novel findings reported herein strongly suggest that post‐transcriptional regulation of genes by miRNAs, coupled with the changes of miRNA processing machinery in the chorioamniotic membranes, plays a role in pregnancy and parturition. Furthermore, the expression level of Dicer in the chorioamniotic membranes dichotomizes pathological preterm labour and physiological spontaneous labour at term. Published in 2008 by John Wiley & Sons, Ltd.

Chorioamnionitis and increased galectin-1 expression in PPROM - An anti-inflammatory response in the fetal membranes?

Problem Galectin‐1 can regulate immune responses upon infection and inflammation. We determined galectin‐1 expression in the chorioamniotic membranes and its changes during histological chorioamnionitis.

Inactivation of the miR-183/96/182 Cluster Decreases the Severity of Pseudomonas aeruginosa-Induced Keratitis

PURPOSE The microRNA-183/96/182 cluster (miR-183/96/182) plays important roles in sensory organs. Because the cornea is replete with sensory innervation, we hypothesized that miR-183/96/182 modulates the corneal response to bacterial infection through regulation of neuroimmune interactions. METHODS Eight-week-old miR-183/96/182 knockout (ko) mice and their wild-type littermates (wt) were used. The central cornea of anesthetized mice was scarred and infected with Pseudomonas aeruginosa (PA), strain 19660. Corneal disease was graded at 1, 3, and 5 days postinfection (dpi). Corneal RNA was harvested for quantitative RT-PCR. Polymorphonuclear neutrophils (PMN) were enumerated by myeloperoxidase assays; the number of viable bacteria was determined by plate counts, and ELISA assays were performed to determine cytokine protein levels. A macrophage (Mϕ) cell line and elicited peritoneal PMN were used for in vitro functional assays. RESULTS MicroRNA-183/96/182 is expressed in the cornea, and in Mϕ and PMN of both mice and humans. Inactivation of miR-183/96/182 resulted in decreased corneal nerve density compared with wt mice. Overexpression of miR-183/96/182 in Mϕ decreased, whereas knockdown or inactivation of miR-183/96/182 in Mϕ and PMN increased their capacity for phagocytosis and intracellular killing of PA. In PA-infected corneas, ko mice showed decreased proinflammatory neuropeptides such as substance P and chemoattractant molecules, MIP-2, MCP1, and ICAM1; decreased number of PMN at 1 and 5 dpi; increased viable bacterial load at 1 dpi, but decreased at 5 dpi; and markedly decreased corneal disease. CONCLUSIONS MicroRNA-183/96/182 modulates the corneal response to bacterial infection through its regulation of corneal innervation and innate immunity.

ORIGINAL ARTICLE: Chorioamnionitis and Increased Galectin-1 Expression in PPROM - An Anti-Inflammatory Response in the Fetal Membranes?: GALECTIN-1 EXPRESSION IN CHORIOAMNIONITIS

Problem Galectin‐1 can regulate immune responses upon infection and inflammation. We determined galectin‐1 expression in the chorioamniotic membranes and its changes during histological chorioamnionitis.

ORIGINAL ARTICLE: Chorioamnionitis and Increased Galectin‐1 Expression in PPROM – An Anti‐Inflammatory Response in the Fetal Membranes?

Problem Galectin‐1 can regulate immune responses upon infection and inflammation. We determined galectin‐1 expression in the chorioamniotic membranes and its changes during histological chorioamnionitis.